The number of cases of trichinosis reported to Centers for Disease Control has declined steadily, with an average of only 44 cases per year from 1984 through 1988. This decline was almost entirely due to a reduction in cases acquired from ingestion of fresh commercial pork. However, from July 21 through September 3, 1990, 90 (72%) of 125 Southeast Asian refugees from six states and Canada developed trichinosis after attending or eating pork sausage taken from a wedding held in Des Moines, Iowa, on July 14, 1990. Eating uncooked sausage prepared at home from commercially obtained pork was associated with the development of this illness (odds ratio = 34.0, p less than 0.001). Analysis by amount of pork consumed was significant (Mann-Whitney U rank sum test, p less than 0.001). This outbreak of trichinosis in Iowa is the fourth reported within the last 15 years among the 900,000 Southeast Asian refugees resident in the United States and one of the largest reported outbreaks in US history. The continued presence of Trichinella spiralis in commercial pork emphasizes the need for further education and control measures for persons whose dietary habits place them at risk for developing trichinosis.